Kinds of Potentiometry

Potentiometry is a powerful electrochemical method when the OCP is measured using a high-resistance electrometer. This method is a common tool for studying equilibrium systems in electrochemical science and engineering. In noneqnilibrium stndies, OCP measurement is nsnally the first step to find out if the cell of interest works properly. Note that dnring the potentiometric measurements, due to the absence of cnrrent in the circuit, any undesirable potential drops inside the phases are absent. In noneqnilibrinm electrochemical systan, the potential drop between working and reference electrodes (called IR drop) is a serious issue to be taken into account experimentally and/or theoretically. 

The main applications of potentiometry are related to measnring the following values  

Solubility product (equilibrium constant) of slightly solnble salts in water 

Dissociation constant of weak electrolyte, inclnding the ionization constant of water 

Standard thermodynamic properties of reaction, inclnding Gibbs energy 

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